This invention relates to the manufacture of tubular articles and more particularly with an apparatus for removing mandrels from tubular articles.
Tubular articles are generally formed by having material wrapped around a mandrel. A mandrel is a cylindrical axle that serves as a core around which material is wrapped and formed. The mandrel forms the inner dimensions of the item and must be removed after the forming operation is completed.
It is the usual practice in the manufacturing of coverings for pipes to wrap the mat of intermixed fibers and uncured binder into a mandrel, then confine the wrapped mat and mandrel within a hollow mold conforming in shape and dimension with the desired outside configuaation of the article to be produced. Sufficient heat is then applied to the confined object to cure the binder material thereby molding and setting the product into its final shape. After the article has been cured it is necessary to remove the mandrel from the article and to return the mandrel to a storage area from which it can be easily retrieved and used again.
Many devices have been used with varying degrees of success to automatically remove mandrels from cured tubular articles. However, these devices have proved both expensive to manufacture and to operate. It has also been found that these devices are not as efficient as they should be in effectuating a quick removal of the mandrel from the article. Further, few of the present mandrel removing devices are completely automatic.